The present invention relates to golf balls, such as two-piece solid golf balls and three-piece solid golf balls, which are composed of a core and a cover of one or more layer that encloses the core.
Many innovations, such as including within the core and cover portions of the golf ball, or in a clear coating, various color pigments (e.g., blue pigments, violet pigments, red pigments) have hitherto been disclosed for preventing to the extent possible the decline in whiteness that occurs at the surface of a golf ball which is repeatedly used and thereby maintaining a good ball appearance. Such golf balls are described in, for example, JP Pat. No. 3,649,568, JP Pat. No. 3,293,679, JP Pat. No. 3,293,694 and JP-B 4-50029.
JP Pat. No. 3,649,568, which relates to a golf ball, describes a means for conferring a high degree of whiteness without using white paint that involves incorporating specific amounts of a blue pigment and a red pigment into a cover made of an ionomer resin. However, when such a golf ball is used over an extended period of time, the color at the surface of the ball fades due to exposure to direct sunlight and other reasons. Hence, further improvements in such properties as resistance to color fading have been desired.
JP Pat. No. 3,293,679 and JP Pat. No. 3,293,694 disclose the use, as the core material in a golf ball, of a white rubber composition obtained by compounding specific amounts of titanium oxide, blue pigment and violet pigment in a golf ball core-forming rubber composition. However, the resulting one-piece golf ball, while useful on a practice range, is unfit for competitive use.
JP-B 4-50029 discloses, in a golf ball having a cover made of balata rubber, the addition of small amounts of a component which exhibits a blue color and a component which exhibits a violet color to the base resin of a white coating so as to impart a white appearance to the balata cover. However, when the cover is painted white to achieve sufficient whiteness, scuffing of the ball causes the underlying material to become visible, compromising the appearance of the ball.